(a) Field of the Invention
The present invention relates to a sealing structure of a wheel bearing for a vehicle. More particularly, the present invention relates to a sealing structure of a wheel bearing for a vehicle which is mounted between an outer ring and a flange of the wheel bearing for the vehicle and can prevent inflow of foreign materials, and the wheel bearing provided with the same.
(b) Description of the Related Art
Generally, a bearing is disposed between a rotating element and a non-rotating element so as to smooth rotation of the rotating element. Various types of bearings such as a ball bearing, a taper roller bearing, needle bearing, and so on are currently used.
A wheel bearing is one type of such bearings, and rotatably connects a wheel that is the rotating element to a vehicle body that is non-rotating element. The wheel bearing includes an inner ring (and/or a hub) connected to one of a wheel or a vehicle body, an outer ring connected to the other of the wheel or the vehicle body, and rolling elements disposed between the outer ring and the inner ring.
Since such the wheel bearing is mounted at the wheel of the vehicle, the wheel bearing is always exposed to foreign materials such as dust and moisture. If the foreign materials enter an inside of the wheel bearing, particularly a portion on which the rolling elements are mounted, raceways that are grinded may be damaged. The damaged raceways may generate noise and vibration when the wheel bearing operates and may shorten a lifetime of the wheel bearing. Therefore, sealing apparatus for preventing inflow of the foreign materials may be mounted at one end or both ends of the wheel bearing. Particularly, the sealing apparatus for sealing a space between the outer ring and the hub may be provided to the wheel bearing.
A conventional sealing apparatus includes an inner supporter, a sealing member, and a lip portion. In addition, the sealing apparatus may further include an outer supporter. The inner supporter is mounted on an exterior circumference of one end portion of the outer ring, the outer supporter is mounted on a flange and faces the inner supporter, and sealant is applied to a contacting surface of the outer supporter and the flange so as to seal a gap between the outer supporter and the flange. The lip portion includes a plurality of lips. Some lips contact with the outer supporter and seal a space between the inner supporter and the outer supporter. That is, the plurality of lips prevent inflow of the foreign materials into the sealing apparatus. The sealing member is integrally formed with the lip portion and mounted on the inner supporter.
The conventional sealing apparatus can prevent inflow of the foreign materials to some degree, but the foreign materials (dust or moisture) falling down on the flange may flow into the sealing apparatus.
In addition, a plurality of lips are configured to contact with the outer supporter in order to further prevent inflow of the foreign materials into the sealing apparatus, thereby increasing drag torque of the bearing.
Furthermore, the inflow foreign materials cannot flow out from the conventional sealing apparatus.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.